Using a system composed of a polarized light microscopy and a charge coupled device (CCD), the crack propagation behavior in BaTiO₃ (BTO) crystal under electric field was in situ investigated with the field direction parallel or perpendicular to the crack surface. In addition, the growth behavior of Vickers indentation surface cracks under alternating electric field was also in situ investigated. Three crack propagation modes induced by incompatible domain switching were proposed based on our observation. The electrical boundary condition of the crack surface was also characterized by measuring and comparing the hysteresis loop of a perfect BTO crystal without crack and a BTO crystal completely fractured in half. Results demonstrate that the electrical boundary condition of a fresh natural crack is permeable, and evolves from permeable to partial permeable during cyclic electric field loading.

使用由偏振光显微镜和电荷耦合器件 (CCD) 组成的系统，BaTiO _{3 中}的裂纹扩展行为(BTO) 晶体在电场下进行原位研究，电场方向平行或垂直于裂纹表面。此外，还原位研究了交变电场下维氏压痕表面裂纹的生长行为。根据我们的观察，提出了由不兼容域切换引起的三种裂纹扩展模式。裂纹表面的电边界条件也通过测量和比较没有裂纹的完美 BTO 晶体和完全断裂一半的 BTO 晶体的滞后回线来表征。结果表明，新的天然裂缝的电边界条件是可渗透的，并在循环电场加载期间从可渗透到部分可渗透。